Study links air pollution to risk of rare nerve disease
A Canadian study out in 2025 has found that people exposed to more sulfur dioxide (SO2)—a pollutant from burning fossil fuels—face a higher risk of developing ALS, a rare and deadly nerve disease.
Researchers compared 304 ALS patients with 1,207 similar people and tracked their SO2 exposure based on where they lived.
ALS patients had higher SO2 exposure than others
ALS patients had higher SO2 exposure than others, even if they lived in places that met current air quality standards.
The link was strongest for pollution levels prior to symptom onset, suggesting that early environmental factors might play a role.
Study adds weight to calls for tougher controls on SO2 emissions
The SO2-ALS connection stayed strong even after factoring in things like income and neighborhood.
Other pollutants didn't show the same effect.
Since ALS is both rare and serious—with most people dying within three years—this study adds weight to calls for tougher controls on SO2 emissions to help protect public health.